. . The inverse cosecant function The cosecant function, cosec : ] [ , ∪ →−∞− ∪ ∞ is bijective in the restricted domain − ∪ . So, the inverse cosecant function is defined with the domain ] [ , −∞− ∪ ∞ and the range − ∪ Definition .
The inverse cosecant function cosec − −∞− ∪ ∞→− ∪ : ( ] [ , is defined by cosec − ( ) y if and only if cosec y and y ∈− ∪